Emails sent to a particular group of contacts xxxxx@domain.com are returned as undeliverable.
The error message is as follows:
Subject: RE: A couple of items
Sent: 01/10/2012 8:53 AM
The following recipient(s) cannot be reached:
"name of person email was sent to" on 01/10/2012 8:53 AM
550 Requested action not taken: mailbox unavailable or not local
Emailing any other contact functions correctly.
Thank-you for your time and help.